diff --git a/Lib/inspect.py b/Lib/inspect.py index fefcddb85cb..f0c12479edb 100644 --- a/Lib/inspect.py +++ b/Lib/inspect.py @@ -1530,9 +1530,6 @@ def signature(obj): if not callable(obj): raise TypeError('{!r} is not a callable object'.format(obj)) - if _signature_is_builtin(obj): - return Signature.from_builtin(obj) - if isinstance(obj, types.MethodType): # In this case we skip the first parameter of the underlying # function (usually `self` or `cls`). @@ -1570,6 +1567,9 @@ def signature(obj): return sig.replace(parameters=new_params) + if _signature_is_builtin(obj): + return Signature.from_builtin(obj) + if isinstance(obj, types.FunctionType): return Signature.from_function(obj) diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py index 2ef3ca2270f..4f19f29165d 100644 --- a/Lib/test/test_inspect.py +++ b/Lib/test/test_inspect.py @@ -1655,6 +1655,21 @@ class TestSignatureObject(unittest.TestCase): __call__ = type test_callable(ThisWorksNow()) + @unittest.skipIf(MISSING_C_DOCSTRINGS, + "Signature information for builtins requires docstrings") + def test_signature_on_decorated_builtins(self): + func = _testcapi.docstring_with_signature_with_defaults + + def decorator(func): + @functools.wraps(func) + def wrapper(*args, **kwargs) -> int: + return func(*args, **kwargs) + return wrapper + + decorated_func = decorator(func) + + self.assertEqual(inspect.signature(func), + inspect.signature(decorated_func)) def test_signature_on_builtins_no_signature(self): with self.assertRaisesRegex(ValueError, 'no signature found for builtin'):